1. Field of the Invention
The present invention relates to a microfilm searching and reading device for selecting a cartridge containing a target image from stored microfilm cartridges and then reading out the target image by an image sensor. The present invention further relates to a scanner which is to be assembled in the aforementioned microfilm searching and reading device.
2. Prior Art Statement
There is known an apparatus for selectively taking out a microfilm cartridge containing a target image from a multiplicity of cartridges stored in storing racks and then reading the target image so that image data are converted into digital signals. The output image data may be supplied to a display device such as cathode ray tube, a printer or a facsimile, or may be combined with outputs from other data processing units to be printed so that desired data sheets or documents are printed out. Thus, by converting the image data in microfilms into digital signals or data, it becomes possible to realize cooperation with a digital image processing device of different type directly or through a data communication network to improve the utility of the microfilm.
One of the known systems for storing and handling microfilm cartridges is a rotary rack type device, which comprises plural shelves disposed around the periphery of a rotary drum for storing thereon a number of microfilm cartridges, and take-out means arranged at a predetermined location facing to the periphery of the rotary shelves, said take-out means being movable in the vertical direction. In operation of this known rotary rack type device, the drum is rotated so that the rack containing the desired cartridge is facing to the take-out means, and then the take-out means is moved in the vertical direction to take out the desired cartridge which is transferred to an image reader having an image sensor.
However, since the relatively heavy rotary shelves must be rotated in the initial step, and then the take-out means are moved in the vertical direction in the next step, the time costed for taking out the desired cartridge, i.e. the access time, is redundantly long in addition to a large area required for the installation thereof.
Another known system comprises a fixed storing shelf having a configuration similar to a bookshelf, and a carrier arranged in front of the storing shelf to move in a plane facing and covering the entire front area of the shelf. In operation, the carrier moves two-dimensionally in the X and Y directions along the vertical plane facing the front area of the storing shelf to be positioned just before the desired cartridge which is then grasped and taken out by the carrier to be delivered to an image reader disposed at a fixed position. However, this known system has a disadvantage in that the access time is prolonged since the cartridge is first taken out from the storing shelf by the carrier and then delivered from the carrier to the image reader. Another disadvantage of this known system is that the scanner is liable to become large in size since the target image is read from a selected cartridge, and thus it becomes difficult to design a compact scanner which can be snugly contained in the storage rack. For these reason the known system requires a large space and it cannot be adapted for a small scale system.
There is also a maintenance problem. That is, when dusts or other stains stick to the optical system of image reader of the scanner contained in the storage rack, difficulty is encountered to remove such dusts or stains.